Inclusion Criteria:

1. Adults ≥ 18 years of age at time of study vaccination.

2. Previously vaccinated with ≥ 3 doses of an authorized/approved COVID-19 vaccine with
the last dose administered ≥ 6 months prior to study vaccination.

3. Willing and able to give informed consent prior to study enrollment and to comply
with study procedures.

4. Female participants of childbearing potential (defined as any participant who has
experienced menarche and who is NOT surgically sterile [ie, hysterectomy, bilateral
tubal ligation, or bilateral oophorectomy] or postmenopausal [defined as amenorrhea
≥ 12 consecutive months]) must agree to be heterosexually inactive from at least 28
days prior to enrollment and through the end of the study OR agree to consistently
use a medically acceptable method of contraception listed below from ≥ 28 days prior
to enrollment and through the end of the study.

1. Condoms (male or female) with spermicide (if acceptable in country)

2. Diaphragm with spermicide

3. Cervical cap with spermicide

4. Intrauterine device

5. Oral or patch contraceptives

6. Norplant®, Depo-Provera®, or other in country regulatory approved contraceptive
method that is designed to protect against pregnancy

7. Abstinence, as a form of contraception, is acceptable if in line with the
participant's lifestyle

5. Is medically stable, as determined by the investigator (based on review of health
status, vital signs [to include body temperature], medical history, and physical
examination [to include body weight]). Vital signs must be within medically
acceptable ranges prior to study vaccination. Blood pressure must be ≤ 160/100 mmHg;
any participant who is otherwise eligible with a blood pressure of ≥ 160/100 mmHg
may be retested onsite several times over a 3-hour interval to achieve a lower blood
pressure.

6. Agrees not to participate in any research involving receipt of investigational
products (drug/biologic/device) including other SARS-CoV-2 prevention or treatment
trials for the duration of the study.

Exclusion Criteria:

1. Current participation in research involving receipt of investigational products
(drug/biologic/device).

2. Received any other vaccine within 28 days prior to study vaccination or plans to
receive any other vac-cine within 28 days after study vaccination. Influenza
vaccines can be administered up to 14 days before study vaccination.

3. Any known history of allergies to products contained in the investigational product
in the participant's lifetime.

4. Any known history of anaphylaxis to any prior vaccine in the participant's lifetime.

5. Known history of myocarditis or pericarditis in the participant's lifetime.

6. Suspected or known history of alcohol abuse or drug addiction within 2 years prior
to study vaccination that, in the opinion of the investigator, might interfere with
protocol compliance.

7. Autoimmune or immunodeficiency disease/condition (iatrogenic or congenital) that
requires the use of immune modulators.

8. Chronic administration (defined as > 14 continuous days) of immunosuppressant,
systemic glucocorticoids, or other immune-modifying drugs within 90 days prior to
study vaccination (Day 0). Persons with human immunodeficiency virus are excluded

9. Received any prohibited medication, immunoglobulin, blood-derived products, or
immunosuppressant drugs within 90 days prior to study vaccination (Day 0).

10. Active cancer (malignancy) on chemotherapy within 3 years prior to first study
vaccination (with the exception of adequately treated non-melanomatous skin
carcinoma or lentigo maligna and uterine cervical carcinoma in situ without evidence
of disease, at the discretion of the investigator).

11. Participants who are breastfeeding, pregnant, or who plan to become pregnant prior
to the end of study.

12. Any other condition that, in the opinion of the investigator, would pose a health
risk to the participant if enrolled or could interfere with evaluation of the study
vaccine or interpretation of study results (including neurologic or psychiatric
conditions likely to impair the quality of safety reporting).

13. Study team member or immediate family member of any study team member (inclusive of
Sponsor, clinical research organization [CRO], and study site personnel involved in
the conduct or planning of the study).

14. Temperature of > 38°C (oral measurement) or respiratory symptoms in the past 3 days
(ie, cough, sore throat, difficulty breathing) leading up to Day 0.